Practical Evaluation Technology

Handling all types of situational evaluations for mobile electronic devices

A wide range of materials, such as gaskets for impact absorption and double-coated adhesive tape, are used in mobile electronic devices, a typical example of which is the mobile phone. The performance demanded of these materials is evaluated in usage conditions that take every imaginable situation into consideration, with the results being used to improve product reliability.

Wide range of materials for mobile electronic devices

Dustproofing Evaluation

Mobile computing devices, which are often used outdoors, require effective dustproofing. With dustproofing evaluation, gasket material is installed in an evaluation container, which is then placed in a dusty environment. The number of particles of dust that successfully penetrate the gasket and end up in the container are then counted using a particle counter. The degree of dustproofing of the gasket material is determined from the ratio of dust particles that penetrated the gasket material to the number of dust particles in the dusty environment. By vibrating the container it is possible to observe the influence of shocks and vibration.

Drop impact evaluation system overview and strain and acceleration waveform at the time of drop impact

Observation of mobile phone deflection at the time of drop impact using a high-speed camera

Material Evaluation

Gasket material is used in mobile electronic devices. In order to evaluate the impact absorption rate, gasket material is placed in a pendulum test device and impacted with a steel ball. The impact absorption rate is determined from the force generated on the gasket material. The impact absorption rate can also be determined by changes in compression rate after the gasket material has been compressed. Furthermore, in tests using a servo-type load testing device, it is possible to observe the process from the compression to the unloading of the material using a high-speed camera and evaluate speed reliance over a broad range. In a compression test at a specific speed, it is possible to evaluate stress and strain characteristics and their temperature reliance, as well as estimate lifespan through repeated testing.

Measuring using a pendulum test device.

Observation using a servo-type load testing device and high-speed camera